Various types of structures for coupling two coupling bodies and maintaining thereof in a separable manner (coupling/uncoupling structures), which are employed in various types of applications from the field of daily life to the field of advanced technologies and have structures suitable for the applications, are proposed.
When the field of the cosmonautic vehicle is exemplified as an example for the field of advanced technology, a coupling/uncoupling structure is employed in order to separate two connected cosmonautic vehicles. For example, Patent Literature 1 discloses an uncoupling mechanism for connecting an artificial satellite and a rocket as cosmonautic vehicles in a separable manner, and a coupling/uncoupling structure is contained in the aforementioned uncoupling mechanism.
The aforementioned uncoupling mechanism comprises flange sections, which are provided in each of a coupling end of a rocket main frame (a rocket main body) and a coupling end of an artificial satellite, a fitting member, which is fitted to the aforementioned flange section from the outside thereof in the state that these flange sections are mutually coupled, and a band member wound and turned around the outer circumference of the coupling section containing the aforementioned fitting member (for example, Marman clamp band). The both ends of the band member are coupled to each other by a coupling member composed of a bolt or the like in the state that the outer circumference of the fitting member is tightened, and a breaking device is mounted in the aforementioned coupling member. The coupling member is broken with the breaking device on the occasion of the separation of the artificial satellite, and thus the coupling between the end sections of the band member is released, so that the artificial satellite would be separated from the rocket main frame. The aforementioned coupling member and the disconnecting device correspond to the above-described coupling/uncoupling structure.
An explosive bolt or a pyrotechnic fastener is generally employed for the coupling/uncoupling structure of the aforementioned configuration. Typical explosive bolt is configured to include an explosive provided in an axis core of a bolt, and the explosive is exploded to break the bolt when the artificial satellite is separated, thereby releasing the coupling of the band member.
Meanwhile, large-scale artificial satellites are in the practical use in recent years, and the fight speed of the rockets that is coupled with the artificial satellite is tended to be increased. When the size of the cosmonautic vehicle is increased and the flight speed thereof is increased as described above, it is necessary to sufficiently tighten the coupling section between the cosmonautic vehicles by the band member. Hence, larger fastening force would be required for the coupling/uncoupling structure for coupling the band member.
In the case of composing the coupling/uncoupling structure with the aforementioned explosive bolt, when sufficient fastening force cannot be achieved with a single explosive bolt, a plurality of explosive bolts may be employed. However, since the coupling of the band member with the explosive bolt is created in the state of tightening the aforementioned band member, the use of a plurality of explosive bolts deteriorates the workability for the coupling. Also, all of plurality of explosive bolts must be firmly and entirely broken in order to appropriately separate the cosmonautic vehicle off, and therefore it is necessary to increase the explosive force of the explosive and it is also necessary to enhance the reliability for the ignition of the explosive. Consequently, the explosive bolt may be possibly an expensive product, and in addition, larger bombardment is generated by the explosive force in the breaking of the explosive bolt to possibly cause an impact on the cosmonautic vehicle.
Thus, conventionally, a coupling/uncoupling structure without employing the pyrotechnic composition such as the explosive bolt and the like is proposed. For example, Patent Literature 2 proposes a coupling/uncoupling device configured to comprise trapezoid tooth profile sections provided in an end section of a band member and configured to mutually engage between the inner surface and the outer surface thereof, a cam body for pressing the aforementioned trapezoid tooth profile section and an actuator for actuating the cam body. In this configuration, the band member is opened by driving the actuator to actuate the cam body, and thus when the pressing condition for the band is released, the band is opened, resulting in that the trapezoid tooth profiles of the other end are mutually separated.
Also, Patent Literature 3 discloses a band opening mechanism as an example of a coupling/uncoupling structure utilizing a release mechanism comprising pins, and valve needles. The valve needle serves as closing a duct that connects an annular chamber filled with a viscous substance (lead) therein and an empty chamber. The annular chamber is formed between a housing and a piston, which are fitted to each other, and the empty chamber is formed in a cap on the piston. When the aforementioned release mechanism is actuated, the pin displaces the position of the valve needle, so that the viscous substance transfers from the annular chamber to the through the duct. This causes the piston continually moving from the housing, so that the band member is opened at a predetermined time that is previously defined.
According to Patent Literature 2 or 3, it is disclosed or suggested that larger fastening force can be achieved without a need for larger force for releasing the coupling of the band member and in the state that the band member is coupled by employing the coupling/uncoupling structures disclosed in these Patent Literatures.